TY - BOOK AU - Hickok,William Orville TI - The minerals of Pennsylvania: Iron ores of Pennsylvania, AV - TN24.P4 A7 PY - 1939/// CY - Harrisburg, Pa. PB - Department of Internal Affairs, Topographic and Geologic Survey KW - Iron ores KW - Pennsylvania N1 - At head of title: Pennsylvania Geological survey, Fourth series; With Ashley, G. H. The undeveloped mineral resources of Pennsylvania. 1933. (Bulletin M18-A); Bibliographical footnotes ER -